My research involves superconducting thin films, Josephson junctions and especially Superconducting Quantum Interference Devices (SQUIDs) and their applications. SQUIDs are unrivalled as magnetic flux sensors over a wide frequency range from dc up to GHz and beyond. They have many applications in biomagnetism, non destructive evaluation, geophysics and fundamental metrology. For the past 12 years I worked on developing a range of superconducting devices and applications based on high temperature superconductor (HTS) thin films grown by pulsed laser deposition. Since I arrived at UCL in late 2006 my group has developed a range of niobium-based nano-scale SQUID sensors. Such devices have many potential applications in spintronics, quantum information processing and magnetic nanoparticle detection.

Niobium SQUID fabricated at UCL using our focussed ion beam (FIB) facility. The device incorporates 150 nm wide nanobridges (inset) as the active Josephson elements.

Recent publications

• "Spatial resolution assessment of Nano-SQUIDs made by focused ion beam" [PDF File] L. Hao, J. C. Macfarlane, J. C. Gallop, E. Romans, D. Cox, D. Hutson and J. Chen
• "HTS SQUID NDE of curved surfaces using background field cancellation techniques" [PDF File] Shane Keenan, Edward J. Romans and Gordon B. Donaldson